The present invention relates generally to fuel cells, and more particularly to fuel cells having embedded current collectors and methods of making the same.
Fuel cells use an electrochemical energy conversion of hydrogen and oxygen into electricity and heat. It is anticipated that fuel cells may be able to replace primary and secondary batteries as a portable power supply. In fuel cells, the fuel (containing a source of hydrogen) is oxidized with a source of oxygen to produce (primarily) water and carbon dioxide. The oxidation reaction at the anode, which liberates electrons, in combination with the reduction reaction at the cathode, which consumes electrons, results in a useful electrical voltage and current through the load.
As such, fuel cells provide a direct current (DC) voltage that may be used to power motors, lights, electrical appliances, etc. A solid oxide fuel cell (SOFC) is one type of fuel cell that may be useful in portable applications.
It is known that anode and cathode electrodes typically suffer from undesirable ohmic losses. As such, current collectors (high efficiency electron conductors) are typically placed on the top of the anode and/or cathode electrodes. However, current collectors placed on top of the anode/cathode may generally suffer from relatively poor current collector efficiency. It is also known that fuel cells suffer from undesirable catalytic/activation polarization losses. In addition to this, thin film current collectors generally agglomerate at high temperatures and become discontinuous. As a result, the current collectors lose efficiency.